1. Field of the Invention
This invention relates to a method of etching a bond pad, a method of using an etching apparatus and a semiconductor device.
2. Discussion of the Background
During the semiconductor manufacturing process, one of the latter steps in fabrication is the formation of bonding pads, which are used to connect an integrated circuit to a device. The bonding pads serve as a connection point for conductive wires.
In order to form bonding pads, a conductive material layer is formed to desired areas of an integrated circuit, which themselves form the site of attachment to wires.
Bonding pads are typically formed by successively depositing a patterned conductive material, a dielectric material and a passivation layer, followed by patterned etching of the passivation and dielectric layers, providing an exposed surface of the conductive material.
During the etching process, it has now been discovered that overetching of the passivation and dielectric layers can result in some etching of the underlying conductive material. In some cases, etching of the conductive material produces a non-volatile material, which can be dispersed throughout the etching chamber. The production of significant amounts of non-volatile etch by-products can pose problems in that the non-volatile materials can contaminate a semiconductor wafer, and therefore, must be periodically removed from the chamber. This is a particularly significant problem when the same etching chamber is used to conduct different etching processes. More specifically, non-volatile etching by-products of a conductive material layer can serve as a contaminant in subsequent etching steps.
Accordingly, a selective etching technique that reduces the production of non-volatile by-products of the conductive material is desired.